feat: Emby 兼容层完整实现 + 多模块功能增强

## Emby/Jellyfin 兼容层 (emby_compat.go / emby.go)
- 新增 SystemInfoPublic、FindUser、Items、Item、LatestItems、ResumeItems
- 新增 SetFavorite、MarkPlayed、RecordProgress 用户播放状态同步
- 新增 itemPayload、mediaSource、mediaStreams 媒体信息组装
- 双前缀路由 /emby/* 和 / 根路径，兼容 Infuse/Yamby/Senplayer/Kodi
- 新增 Ping、SystemEndpoint、AuthByName 端点
- emby.go 扩展对应 handler 函数

## 站点适配器 (site_adapter.go / site.go)
- SiteConfig 扩展 UserAgent/Timeout/Extra/FlareSolverrURL 字段
- doRequest() GET 请求支持 FlareSolverr 代理绕过 Cloudflare/WAF
- MTeam api_key 认证改为 Authorization: Bearer 格式
- Search() 重构为 sync.WaitGroup 并发执行，提升多站搜索性能
- siteModelToConfig() 改为 SiteService 方法，按 BrowserEmulation 填充 FlareSolverrURL

## 图片代理 (image_proxy.go)
- 重构图片代理服务，支持更多来源和缓存策略

## 下载管理 (downloads.go / download_clients.go / qbittorrent.go)
- 下载任务增强：状态管理、进度追踪优化
- qBittorrent 客户端连接稳定性改进

## 刮削与数据库 (scraper.go / tmdb.go / repository.go)
- 刮削器增强 TMDB 集成，补全元数据字段
- repository 扩展查询方法

## 前端 (web/src/)
- HomePage: 首页布局重构，按媒体库分组展示，系列聚合优化
- DiscoverPage: 发现页增强，错误处理改进（API key 缺失/网络错误分离）
- PosterWallPage: 海报墙优化，系列聚合展示
- MediaCard: 媒体卡片优化
- PlayerPage: 播放器改进
- 新增 utils/groupSeries.ts: 系列聚合工具函数
- .gitignore: 添加 .tmp_* 临时文件排除规则

web/src/pages/DiscoverPage.tsx

@@ -1,42 +1,64 @@
 import { useEffect, useState } from 'react'
-import { Sparkles, AlertTriangle, ExternalLink } from 'lucide-react'
+import { Sparkles, AlertTriangle, ExternalLink, Wifi } from 'lucide-react'
 import { Link } from 'react-router-dom'
 
 import { discoverAPI, type DiscoverItem } from '../api/discover'
 import { imageURL } from '../api/client'
 
+// 判断后端返回的错误是不是"未配置 API key"。其它（网络超时/被墙/上游 5xx）
+// 都归为"网络/上游故障"，避免误导用户去再配一次 key。
+function isMissingKey(err?: string): boolean {
+  if (!err) return false
+  const low = err.toLowerCase()
+  return low.includes('api key') || low.includes('apikey') || low.includes('not configured')
+}
+
+function isNetworkError(err?: string): boolean {
+  if (!err) return false
+  const low = err.toLowerCase()
+  return (
+    low.includes('deadline exceeded') ||
+    low.includes('timeout') ||
+    low.includes('no such host') ||
+    low.includes('connection refused') ||
+    low.includes('eof') ||
+    low.includes('tls') ||
+    low.includes('reset')
+  )
+}
+
 export function DiscoverPage() {
   const [trending, setTrending] = useState<DiscoverItem[]>([])
   const [popular, setPopular] = useState<DiscoverItem[]>([])
+  const [trendingErr, setTrendingErr] = useState<string | undefined>()
+  const [popularErr, setPopularErr] = useState<string | undefined>()
   const [loading, setLoading] = useState(true)
-  const [error, setError] = useState<string | null>(null)
 
   useEffect(() => {
     setLoading(true)
-    setError(null)
-    
     Promise.all([
-      discoverAPI.trending().catch((err) => {
-        console.error('Failed to fetch trending:', err)
-        return [] as DiscoverItem[]
-      }),
-      discoverAPI.popular().catch((err) => {
-        console.error('Failed to fetch popular:', err)
-        return [] as DiscoverItem[]
-      }),
+      discoverAPI.trending().catch((err) => ({
+        items: [] as DiscoverItem[],
+        error: err instanceof Error ? err.message : String(err),
+      })),
+      discoverAPI.popular().catch((err) => ({
+        items: [] as DiscoverItem[],
+        error: err instanceof Error ? err.message : String(err),
+      })),
     ])
       .then(([t, p]) => {
-        setTrending(t)
-        setPopular(p)
-      })
-      .catch((err) => {
-        setError(err instanceof Error ? err.message : 'Failed to load discover data')
+        setTrending(t.items)
+        setTrendingErr(t.error)
+        setPopular(p.items)
+        setPopularErr(p.error)
       })
       .finally(() => setLoading(false))
   }, [])
 
-  // Check if TMDB API key is likely not configured
-  const isTMDBMissing = !loading && trending.length === 0 && popular.length === 0 && !error
+  const anyErr = trendingErr || popularErr
+  const missingKey = isMissingKey(anyErr)
+  const networkErr = !missingKey && isNetworkError(anyErr)
+  const otherErr = !missingKey && !networkErr && anyErr
 
   return (
     <div className="space-y-8 px-4 py-6 max-w-7xl mx-auto">
@@ -53,26 +75,17 @@ export function DiscoverPage() {
         </div>
       </header>
 
-      {/* Error Alert */}
-      {error && (
-        <div className="rounded-2xl bg-red-500/10 border border-red-500/20 p-4 flex items-center gap-3">
-          <AlertTriangle className="h-5 w-5 text-red-400 flex-shrink-0" />
-          <p className="text-red-300">{error}</p>
-        </div>
-      )}
-
-      {/* Loading State */}
       {loading && <DiscoverSkeleton />}
 
-      {/* TMDB API Key Missing */}
-      {isTMDBMissing && (
+      {/* TMDb API Key 未配置 */}
+      {!loading && missingKey && (
         <div className="rounded-2xl bg-amber-500/10 border border-amber-500/20 p-6 text-center space-y-4">
           <div className="mx-auto w-16 h-16 rounded-full bg-amber-500/10 flex items-center justify-center">
             <AlertTriangle className="h-8 w-8 text-amber-400" />
           </div>
           <h3 className="text-lg font-semibold text-white">TMDb API Key 未配置</h3>
           <p className="text-sm text-slate-400 max-w-md mx-auto">
-            您需要配置 TMDb API Key 才能查看发现内容。请前往管理后台配置。
+            您需要在管理后台填入 TMDb API Key 才能查看发现内容。
           </p>
           <Link
             to="/admin"
@@ -84,14 +97,42 @@ export function DiscoverPage() {
         </div>
       )}
 
+      {/* 网络无法访问 TMDb */}
+      {!loading && networkErr && (
+        <div className="rounded-2xl bg-orange-500/10 border border-orange-500/20 p-6 text-center space-y-4">
+          <div className="mx-auto w-16 h-16 rounded-full bg-orange-500/10 flex items-center justify-center">
+            <Wifi className="h-8 w-8 text-orange-400" />
+          </div>
+          <h3 className="text-lg font-semibold text-white">无法连接到 TMDb</h3>
+          <p className="text-sm text-slate-400 max-w-lg mx-auto">
+            服务器到 <code className="font-mono text-orange-300">api.themoviedb.org</code> 的连接超时。
+            通常是因为部署机器没有走代理。可以在系统环境变量里设置
+            <code className="font-mono text-orange-300 mx-1">HTTPS_PROXY</code>，
+            或在「外部 API」配置里填写自建反代地址（tmdb_api_proxy / tmdb_image_proxy）。
+          </p>
+          <details className="text-xs text-slate-500 max-w-lg mx-auto text-left">
+            <summary className="cursor-pointer hover:text-slate-400">查看原始错误</summary>
+            <pre className="mt-2 p-2 rounded bg-black/40 overflow-x-auto whitespace-pre-wrap">{anyErr}</pre>
+          </details>
+        </div>
+      )}
+
+      {/* 其它错误 */}
+      {!loading && otherErr && (
+        <div className="rounded-2xl bg-red-500/10 border border-red-500/20 p-4 flex items-center gap-3">
+          <AlertTriangle className="h-5 w-5 text-red-400 flex-shrink-0" />
+          <p className="text-red-300">{otherErr}</p>
+        </div>
+      )}
+
       {/* Content Rows */}
-      {!loading && !isTMDBMissing && (
+      {!loading && !missingKey && (
         <div className="space-y-10">
           {trending.length > 0 && <ContentRow title="今日趋势" items={trending} />}
           {popular.length > 0 && <ContentRow title="热门电影" items={popular} />}
-          
-          {/* Empty State (TMDB configured but no data) */}
-          {trending.length === 0 && popular.length === 0 && (
+
+          {/* TMDB 配置 OK 但本次没拿到任何条目（极少见） */}
+          {!networkErr && trending.length === 0 && popular.length === 0 && !otherErr && (
             <div className="text-center py-12">
               <p className="text-slate-500">暂无发现内容</p>
             </div>
@@ -106,7 +147,7 @@ function ContentRow({ title, items }: { title: string; items: DiscoverItem[] })
   return (
     <section className="space-y-4">
       <h2 className="font-display text-2xl font-semibold text-white pl-1">{title}</h2>
-      <div className="grid grid-cols-2 gap-5 sm:grid-cols-3 md:grid-cols-4 lg:grid-cols-5 xl:grid-cols-6">
+      <div className="grid grid-cols-3 gap-4 sm:grid-cols-4 md:grid-cols-5 lg:grid-cols-7 xl:grid-cols-8">
         {items.map((item) => (
           <DiscoverCard key={item.tmdb_id} item={item} />
         ))}
@@ -117,8 +158,7 @@ function ContentRow({ title, items }: { title: string; items: DiscoverItem[] })
 
 function DiscoverCard({ item }: { item: DiscoverItem }) {
   return (
-    <div className="group relative overflow-hidden rounded-2xl border border-white/5 bg-surface-800/60 hover:border-primary-500/30 transition-all duration-300 hover:shadow-2xl hover:shadow-primary-500/10 hover:-translate-y-1">
-      {/* Poster */}
+    <div className="group relative overflow-hidden rounded-xl border border-white/5 bg-surface-800/60 hover:border-primary-500/30 transition-all duration-300">
       <div className="aspect-[2/3] w-full bg-surface-900 relative overflow-hidden">
         {item.poster_url ? (
           <img
@@ -129,26 +169,22 @@ function DiscoverCard({ item }: { item: DiscoverItem }) {
             className="h-full w-full object-cover group-hover:scale-105 transition-transform duration-500"
           />
         ) : (
-          <div className="flex h-full w-full items-center justify-center text-slate-600">
+          <div className="flex h-full w-full items-center justify-center text-slate-600 text-xs">
             无海报
           </div>
         )}
-        
-        {/* Rating Badge */}
         {item.rating > 0 && (
-          <div className="absolute top-3 right-3 rounded-lg bg-black/70 backdrop-blur-sm px-2 py-1 text-sm font-semibold text-yellow-400 border border-yellow-400/30">
+          <div className="absolute top-1.5 right-1.5 rounded-md bg-black/70 backdrop-blur-sm px-1.5 py-0.5 text-[11px] font-semibold text-yellow-400 border border-yellow-400/30">
             ★ {item.rating.toFixed(1)}
           </div>
         )}
       </div>
-
-      {/* Info */}
-      <div className="p-4 space-y-1">
-        <p className="font-medium text-white truncate group-hover:text-primary-400 transition-colors">
+      <div className="px-2.5 py-2 space-y-0.5">
+        <p className="text-xs font-medium text-white truncate group-hover:text-primary-400 transition-colors">
           {item.title}
         </p>
         {item.year > 0 && (
-          <p className="text-sm text-slate-500">{item.year}</p>
+          <p className="text-[11px] text-slate-500">{item.year}</p>
         )}
       </div>
     </div>
@@ -161,9 +197,9 @@ function DiscoverSkeleton() {
       {[1, 2].map((section) => (
         <section key={section} className="space-y-4">
           <div className="h-8 w-48 rounded-lg bg-surface-800 animate-pulse" />
-          <div className="grid grid-cols-2 gap-5 sm:grid-cols-3 md:grid-cols-4 lg:grid-cols-5 xl:grid-cols-6">
-            {[1, 2, 3, 4, 5, 6].map((i) => (
-              <div key={i} className="aspect-[2/3] rounded-2xl bg-surface-800 animate-pulse" />
+          <div className="grid grid-cols-3 gap-4 sm:grid-cols-4 md:grid-cols-5 lg:grid-cols-7 xl:grid-cols-8">
+            {[1, 2, 3, 4, 5, 6, 7, 8].map((i) => (
+              <div key={i} className="aspect-[2/3] rounded-xl bg-surface-800 animate-pulse" />
             ))}
           </div>
         </section>